Chronic
ankle instability (CAI) is a common concern for patients with a history of
ankle sprains but can be very challenging to diagnose. Previous studies have validated the multiple-hop test for
assessing functional deficits as well as dynamic postural stability among
participants with CAI. However,
before this test can be applied in the clinical setting it is important to
determine if it can accurately diagnose patients with CAI and if it is
sensitive to change over time. Therefore, the purpose of this study was to
determine if the multiple
hop test is an evaluative (if it could measure change over time) or
discriminative (if it can differentiate patients with and without CAI; 29
participants/group) test for CAI. Inclusion criteria for the patients with CAI
were: 1) history of lateral ankle sprain requiring 2 or more medical consults,
2) complaints of repetitive lateral ankle sprains for more than 6 months, 3)
presence/fear of the ankle “giving way”, and 4) reporting a decreased level of
ankle performance in recreational, competitive, or professional
sports/activities. To complete the multiple hop test the participants were
instructed to hop from and land on one leg through each 11 numbered points. The
participants were instructed to maintain their balance and avoid posture
correction (balance errors). After landing, the participants were told to stand
still and then to resume the single-leg, hands-on hips, start position and then
finally hop to the next point. Both
legs were tested in a random order with a practice trial for each leg. The
participants performed 3 reps on each leg with 3 minutes between reps (30 sec
between legs). The
participants were scored on 3 outcomes: 1) the total number of balance errors
across three trials (range 0 to 30), as assessed on video tape, 2) the average
time taken to complete the test, and 3) the participant-reported perceived
difficulty measured on a 100-mm visual analog scale ranging from 0 = “not
difficult” to 100 = “impossible to
perform.” The authors found that the multiple-hop test was deemed to be an
effective discriminative test for differentiating participants with and without
CAI, based on participants with CAI having poorer performance. For the three
outcomes, the authors determined the optimal cut-offs for differentiating those
with and without CAI: 1) 13.5 errors, 2) 35 seconds to complete the test, and
3) 32.5 mm on the visual analog scale for perceived difficulty. The authors
found that when two of the outcomes were positive (based on the cutoffs above)
the multiple hop test had the best ability to differentiate those with and
without CAI (diagnostic accuracy ~ 83%, sensitivity ~ 86%, specificity ~ 79%) .While
the multiple hop test may be able to discriminate the authors found that the
test’s ability to detect a change may be limited. They calculated that the
minimal detectable change for each outcome was quite large (the minimal
detectable change was based on how much the test varies among the participants
and how the outcomes vary over several trials). To detect changes participants
would need to increase or decrease their outcomes by ~ 7 errors, 2) 6 seconds
to complete the test, and 3) 27 to 55 mm on the visual analog scale for
perceived difficulty.

This
is an important study because it demonstrates that the multiple-hop test may be
capable of discriminating patients with and without CAI but not as effective at
monitoring change over time. It is
important to note that the authors state
that they are not certain which combination of outcomes best illustrates the
presence of CAI. The authors state there are some flaws in the make-up in this
study, and as it stands, more studies are going to need to be done to find
which outcomes help to determine the multiple-hop test's evaluative and
discriminative properties. For example, there are several other approaches to
assess the ability of the multiple-hop test to detect change over time. What
are your thoughts on the use of the multiple-hop test for assessing ankle function?
Are you using anything like it in your setting to assess CAI?

2
comments:

Jay Hertel
said...

The author of the summary raises some important questions about the clinical utility of the the multiple hop test. If CAI status can be established based on injury history and patient self-report of functional status (as was done in this study), what is the added value of a functional performance test to discriminate between patients with and without CAI? I think this issue is amplified more if the functional performance test is not responsive to change as patient health status changes. While the authors report the MDC estimates for the multiple hop test measures, they didn't actually track changes in patient performance over time as part of this study. My suspicion is that this test, like the Star Excursion Balance Test, would actually improve with an adequate rehabilitation program. My personal opinion is that functional tests have greater clinical utility as outcome tools to track progress over time than as diagnostic tools.

Jay, thanks for reading and commenting . I agree with all of the points that you bring up. Based upon the author's previous studies regarding the multiple hop test, I believe that that this study was the next logical step in determining its clinical utility. Thanks, again

Post a Comment

When you submit a comment please click 'Subscribe by Email" (just below the comments) or "Subscribe to: Post Comments (Atom)" (at the bottom of this page) if you would like to receive a notification when another comment has been submitted to this post.

Please note that if you are using Safari and have problems submitting comments you may need to go to your preferences (privacy tab) and stop blocking third party cookies. Sorry for any inconvenience this may pose.